88 research outputs found
The design of the CASOH process pilot to test the decarbonisation of blast furnace gas using the Ca-Cu chemical loop
No full textWe present the design features of a TRL7 pilot under construction in the Arcelor Mittal´s Gas Lab site in Asturias (Spain), to demonstrate the viability of the Calcium Assisted Steel-mill Off-gas Hydrogen (CASOH) process to decarbonise Blast Furnace Gases [1,2,3]. The work is carried out within the EU C4U project (https://c4u-project.eu/, [3]). The CASOH process relies on high-temperature solid looping reactions, carried out in a number of packed-bed reactors that continuously switch between three reaction stages. In a first stage (also called CASOH), there is carbonation of CaO by capture the CO2, including the CO2 formed by the catalysed Water Gas Shift of the CO contained in the BFG. In a second reaction stage, there is oxidation of the WGS Cu catalyst with air. In a third and final stage, there is the exothermic reduction of the CuO with a fuel gas, to drive the decomposition of CaCO3 and generate a concentrated CO2 gas stream while regenerating the CaO used in the first reaction stage. The CASOH TRL7 pilot has been designed to have a single reactor (with a thermally insulated bed of functional Ca and Cu materials of 5 m height and 0.5 m inner diameter), capable to alternate between all three reaction stages. The pilot will be operated at close to atmospheric pressure within the C4U project, but has enhanced capabilities to accommodate pressure swings of up to 10 bar in the future. It can treat 300 Nm3/h of BFG (about 0.3 MWth) from the AM industrial site and generate an equivalent amount of decarbonised N2/H2 rich-gas and up to 0.7 MWth of sensitive heat at high temperature in heat removal stages. First experimental results at TRL7 are expected by the end of 2022, but successful set of results have been obtained at smaller scale (TRL3-4) with the chosen functional materials (a commercial Cu-catalyst and a commercial limestone with adequate mechanical and chemical properties) and presented in other communications at GHGT16 [4,5]
The work and preliminary results of the C4u project on advanced carbon capture for steel industries integrated in Ccus clusters
No full textThis paper provides an overview of the aims, objectives and preliminary findings of the C4U holistic interdisciplinary project, which addresses all the essential elements required for the optimal integration of CO2 capture in the iron and steel industry as part of the Carbon Capture, Utilisation and Storage (CCUS) chain. The project’s scope spans pilot-scale demonstration of two highly efficient CO2 capture technologies at TRL7 designed for optimal integration into an iron and steel plant along with detailed consideration of the safety, environmental, societal, policy and business aspects for successful incorporation of CCUS into the North Sea Port industrial cluster. The new sorbent-based CO2 capture technologies in C4U are known as DISPLACE (high temperature sorption-DISPLACEment process for CO2 recovery) and CASOH (Calcium Assisted Steel-mill Off-gas Hydrogen production). Both approaches involve high-temperature gas-solid separation processes that reduce the exergy penalty associated with CO2 capture. The progress made on the design and construction of pilot-scale CO2 capture test facilities for assessing the technologies’ performance is presented, along with results of uniquely developed mathematical models and laboratory-scale tests performed for gaining understanding of the physical and chemical phenomena underpinning the processes. The use of these results to establish the full-scale design of the technologies for deployment in an integrated steel-mill using process simulation techniques while quantifying the techno-economic and environmental performance in comparison to reference technologies (e.g. amine based CO2 capture) is also discussed. Analysis undertaken to help interface the technologies with CO2 transport and storage infrastructure is described with particular regard to requirements to meet target compositional specifications, operational safety of CO2 pipelines while also carrying impurities and mathematical tools required for the design and operation of a CCUS cluster in view of future expansion. The development of novel business models for facilitating deployment so that the long-term business case can be established through consideration of the concerns of a multitude of various stakeholders and identification of optimal scenarios for overcoming financial risks is discussed. Progress on evaluating societal readiness and public support for CCUS through just transitions in industrial clusters is also presented. The project’s work is expected to demonstrate CO2 capture from an integrated steel-mill in safe and economic CCUS value chains while establishing viable pathways to rollout of CCUS in industrial clusters
Small-scale production of hydrogen via auto-thermal reforming in an adiabatic packed bed reactor:Parametric study and reactor's optimization through response surface methodology
No full textIn this work, a two-dimensional (2-D) heterogeneous reactor model for ATR process is presented. In order to authenticate the developed reactor model outputs, literature results as well as thermodynamic findings produced by employing chemical equilibrium with applications (CEA) software were compared with the model predictions and an excellent agreement was evidenced that corroborates the model's accurate predictive capability. Response surface methodology combined with central composite design was used to investigate the significance of operational parameters on the performance of the ATR process and Parametric optimization was performed to find the optimal operating conditions. Further insights into the ATR process were obtained by studying the effect of temperature, pressure, S/C, oxygen to carbon ratio (O/C) and gas mass flow velocity (Gs) on CH4 conversion, H2 yield (wt. % of CH4) and H2 purity. It was concluded that 973 K, 1.5 bar, S/C of 3.0, O/C of 0.45 and Gs of 0.15 kg/m2s resulted in CH4 conversion and H2 purity up to 97.6% and 71.8%, respectively.</p
Modelling of H₂ production in a packed bed reactor via sorption enhanced steam methane reforming process
No full textThe sorption enhanced steam reforming (SE-SMR) of methane over the surface of 18 wt. % Ni/ Al₂O₃ catalyst and using CaO as a CO₂-sorbent is simulated for an adiabatic packed bed reactor. The developed model accounts for all the aspects of mass and energy transfer, in both gas and solid phase along the axial direction of the reactor. The process was studied under temperature and pressure conditions used in industrial SMR operations. The simulation results were compared with equilibrium calculations and modelling data from literature. A good agreement was obtained in terms of CH₄ conversion, hydrogen yield (wt. % of CH₄ feed), purity of H₂ and CO₂ capture under the different operation conditions such as temperature, pressure, steam to carbon ratio (S/C) and gas mass flux. A pressure of 30 bar, 923 K and S/C of 3 can result in CH₄ conversion and H₂ purity up to 65% and 85% respectively compared to 24% and 49% in the conventional process
Modelling of high purity H2 production via sorption enhanced chemical looping steam reforming of methane in a packed bed reactor
No full textSorption enhanced chemical looping steam reforming of methane (SE-CLSR) relies on the exothermicity of both a metal catalyst’s oxidation and the in situ CO2 capture by carbonation onto a solid sorbent to provide the heat demand of hydrogen (H2) production by steam reforming while generating a nearly pure H2 product. A brief thermodynamic analysis to study the main features of the SE-CLSR process is done prior to the reactor modelling work. Later, one dimensional mathematical model of SE-CLSR process in the packed bed configuration is developed using gPROMS model builder 4.1.0® under the adiabatic conditions. This model combines reduction of the NiO catalyst with the steam reforming reactions, followed by the oxidation of the Ni-based reduced catalyst. The individual models of NiO reduction, steam reforming with in situ CO2 capture on Ca-sorbent, and Ni re-oxidation are developed by using kinetic data available in literature and validated against previous published work. The model of SE-CLSR is then applied to simulate 10 alternative cycles of the fuel and air feed in the reactor. The performance of the model is studied in terms of CH4 conversion, CO2 capture efficiency, purity and yield of H2. The sensitivity of the process is studied under the various operating conditions of temperature, pressure, molar steam to carbon ratio (S/C) and mass flux of the gas phase. In this work, the operating conditions used for the production of H2 represent realistic industrial production conditions.The sensitivity analysis demonstrates that the developed model of SE-CLSR process has the flexibility to simulate a wide range of operating conditions of temperature, pressure, S/C and mass flux of the gas phase
Modelling of H2 production via sorption enhanced steam methane reforming at reduced pressures for small scale applications
No full textThe production of H2 via sorption enhanced steam reforming (SE-SMR) of CH4 using 18 wt. % Ni/ Al2O3 catalyst and CaO as a CO2-sorbent was simulated for an adiabatic packed bed reactor at the reduced pressures typical of small and medium scale gas producers and H2 end users. To investigate the behaviour of reactor model along the axial direction, the mass, energy and momentum balance equations were incorporated in the gPROMS modelbuilder®. The effect of operating conditions such as temperature, pressure, steam to carbon ration (S/C) and gas mass flow velocity (Gs) was studied under the low-pressure conditions (2 – 7 bar). Independent equilibrium based software, chemical equilibrium with application (CEA), was used to compare the simulation results with the equilibrium data. A good agreement was obtained in terms of CH4 conversion, H2 yield (wt. % of CH4 feed), purity of H2 and CO2 capture for the lowest (Gs) representing conditions close to equilibrium under a range of operating temperatures pressures, feed steam to carbon ratio. At Gs of 3.5 kg m-2s-1, 3 bar, 923 K and S/C of 3, CH4 conversion and H2 purity were up to 89% and 86% respectively compared to 44% and 63% in the conventional reforming process
Kinetics study and modelling of steam methane reforming process over a NiO/Al2O3 catalyst in an adiabatic packed bed reactor
No full textKinetic rate data for steam methane reforming (SMR) coupled with water gas shift (WGS) over an 18 wt. % NiO/α-Al2O3 catalyst are presented in the temperature range of 300-700 °C at 1 bar. The experiments were performed in a plug flow reactor under the conditions of diffusion limitations and away from the equilibrium conditions. The kinetic model was implemented in a one-dimensional heterogeneous mathematical model of catalytic packed bed reactor, developed on gPROMS model builder 4.1.0®. The mathematical model of SMR process was simulated, and the model was validated by comparing the results with the experimental values. The simulation results were in excellent agreement with the experimental results. The effect of various operating parameters such as temperature, pressure and steam to carbon ratio on fuel and water conversion (%), H2 yield (wt. % of CH4) and H2 purity was modelled and compared with the equilibrium values
Techno-economic assessment of Blast furnace gas pre-combustion decarbonisation integrated with the power generation
No full textAiming at the iron and steel industry decarbonisation with blast furnace gas (BFG) utilisation, techno-economic feasibility of the pre-combustion carbon capture with methyl diethanolamine (MDEA) is evaluated herein. The effectiveness of water gas shift (WGS) implementation on the capture performance is also investigated. The integration of a power plant with decarbonised fuel from the capture unit is taken into account from both technical and economic perspectives. Aspen Plus® is used to develop the process. The results obtained from the techno-economic analysis showed that the WGS implementation increases the capture efficiency from 46.5% to 83.8%, with increased CO2 capture cost from €39.8/𝑡𝐶𝑂2 to €44.3/𝑡𝐶𝑂2. The sensitivity analysis on the effect of 1) different BFG composition and 2) different carbon capture rate (CCR) on the capture unit integrated with WGS performance is performed. The obtained results revealed that BFG with a lower calorific value is less practical from a techno-economic point of view as it increases the specific primary energy consumption for CO2 capture avoidance (𝑆𝑃𝐸𝐶𝐶𝐴) from 3.3 𝑀𝐽𝐿𝐻𝑉/𝑘𝑔𝐶𝑂2 to 3.8 𝑀𝐽𝐿𝐻𝑉/𝑘𝑔𝐶𝑂2. Moreover, the lower CCR increases the thermal energy of the H2-rich gas from the capture unit from 266.8 MW to 269.6 MW. The techno-economic advantages of the based case do not results beneficial for na environment point of view since at lower CCR the specific CO2 emissions increase from 51 𝑘𝑔𝐶𝑂2/𝐺𝐽𝐿𝐻𝑉 to 70 𝑘𝑔𝐶𝑂2/𝐺𝐽𝐿𝐻𝑉. The fully integrated power plant to the capture unit reveals that the 37.52% (without WGS) and 24.27% (with WGS) efficiencies are achievable through the combined cycle integration. For the combined cycle, the integration of WGS reactor will reduce the CO2 specific emission to 675.1 𝑘𝑔𝐶𝑂2𝑀𝑊ℎ⁄ in comparison to 1391.5 𝑘𝑔𝐶𝑂2𝑀𝑊ℎ⁄ for the case with no WGS
Gasification processes in membrane reactors
No full textIn the quest for sustainable solutions to tackle the ever-increasing global energy crisis and environmental challenges, the integration of gasification and membrane reactor (MR) technologies has emerged as a viable solution. Different options of gasification that can be combined with MR are discussed and some of the most interesting membrane configurations in integrated gasification combined cycle process are presented. Gasification and MR technology integration for H2 generation and CO2 sequestration on an industrial scale is then explored, and its economic assessment has been discussed. A brief overview of waste management from an industrial perspective through integration of municipal solid waste gasification and MR technology elucidating key principles and various possibilities for thermochemical treatment challenges has been expounded. Finally, the chapter describes the future trends in combining gasification and MR technology for sustainable energy production, carbon sequestration, and waste utilization.</p
Carbon-neutral and carbon-negative chemical looping processes using glycerol and methane as feedstock
No full textCarbon-negative and neutral methods to produce H2 and other syngas-derived chemicals are tested and demonstrated in this study through chemical looping reforming of methane or glycerol. A chemical looping reactor provides the heat required to reform the glycerol or methane while having inherent CO2 capture. This is achieved using dynamically operated packed beds. If the glycerol or methane is from a biological source this gives the system the potential for negative emissions. To evaluate the potential of this system, 500 g packed bed of oxygen carriers were cyclically reduced, oxidized, and used to carry out reforming experiments. The reforming process was tested at various pressure (1 – 9 bar) and temperature (600 – 900 °C). These conditions were tested at this scale for the first time. Complete conversion of glycerol is achievable with only small quantities of CH4 slip. The maximum H2 production was achieved at 1 bar and 700 °C producing a H2/CO ratio of 10, this lowered to 9 when the temperature was increased to 900 °C. Adding CO2 to the feed stream along with H2O allows for a H2/CO ratio suitable for the Fischer Tropsch (FT) synthesis. Chemical looping reforming of CH4 with steam was successfully demonstrated in a lab reactor setup at 1 and 5 bar for multiple cycles with CH4 conversion > 99% and controlled heat losses. The temperature and concentration profiles provided identical results for consecutive cycles verifying the continuity and the feasibility of the process
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